Switch mechanisms for operating a plurality of switch contacts are of course well-known. Many use a single switch operator to progressively act on contact pairs to make or break contacts. Others use plunger mechanisms to actuate the contacts. Another form of switch uses cams on a rotating member to operate a plurality of contact sets, as shown in U.S. Pat. No. 3,637,953 issued Jan. 25, 1952 to H. Ruster et al. In that patent, a section of a cylinder is rotated about its axis to move shaped cams mounted on the cylinder to actuate contacts. The cylinder section provides a partial enclosure for the contacting members.